Field of the Invention
The present invention relates to a coating provided on a conductor, and an electronic component having a conductor coated with the coating.
Related Background Art
An electronic component has a signal transmission part for exchange of signals with an external device. For this signal transmission part to perform the exchange of electric signals with the external device, the signal transmission part needs to have high electrical conductivity and therefore copper or a copper-based alloy is generally used as a base material of the signal transmission part. However, copper or the copper-based alloy has the property of being easily corroded by oxygen in air or by corrosive gas, and therefore there has been investigation to form such a coating layer that a nickel plated film and a gold plated film were laid on a surface of the base material, for the purpose of controlling and preventing corrosion.
For example, Japanese Patent Application Laid-open. No. 2010
For example, Japanese Patent Application Laid-open No. 2010-37603 (Patent Literature 1) proposes that an electroless nickel film is formed as an underlying layer on a base material of a connection terminal part and then a displacement electroless gold plated film and a reduction electroless gold plated film are successively formed thereon.